From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 09D15C4338F for ; Mon, 26 Jul 2021 15:44:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC6DC60F38 for ; Mon, 26 Jul 2021 15:44:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235905AbhGZPET (ORCPT ); Mon, 26 Jul 2021 11:04:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:43028 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235772AbhGZPD3 (ORCPT ); Mon, 26 Jul 2021 11:03:29 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E7FB660F37; Mon, 26 Jul 2021 15:43:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627314237; bh=y9nNAFeu4EWk29ChBJOUf/hJlssjVcanevK4L0Mz1+E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lgVrluoTepqV5hifpUkcjFs9kYzfrONordRojZTX6tquBCFh+fDksPHmN82bAXaMd Y8dt5HH5im3bI1tODZoDmrvhmE8bxUveCaGDQIPVUj7ZDHTm4t9Xj/RU96J3tmqsnO lWP7ISA1WC/SRrI1ugMzrTUvrQtlGFNSo0AwHAJw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , Daniel Borkmann , Ilya Leoshkevich , Sasha Levin Subject: [PATCH 4.9 35/60] s390/bpf: Perform r1 range checking before accessing jit->seen_reg[r1] Date: Mon, 26 Jul 2021 17:38:49 +0200 Message-Id: <20210726153825.972077832@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210726153824.868160836@linuxfoundation.org> References: <20210726153824.868160836@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King [ Upstream commit 91091656252f5d6d8c476e0c92776ce9fae7b445 ] Currently array jit->seen_reg[r1] is being accessed before the range checking of index r1. The range changing on r1 should be performed first since it will avoid any potential out-of-range accesses on the array seen_reg[] and also it is more optimal to perform checks on r1 before fetching data from the array. Fix this by swapping the order of the checks before the array access. Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Signed-off-by: Colin Ian King Signed-off-by: Daniel Borkmann Tested-by: Ilya Leoshkevich Acked-by: Ilya Leoshkevich Link: https://lore.kernel.org/bpf/20210715125712.24690-1-colin.king@canonical.com Signed-off-by: Sasha Levin --- arch/s390/net/bpf_jit_comp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 9b15a1dc6628..ed58ebab96cd 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -116,7 +116,7 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1) { u32 r1 = reg2hex[b1]; - if (!jit->seen_reg[r1] && r1 >= 6 && r1 <= 15) + if (r1 >= 6 && r1 <= 15 && !jit->seen_reg[r1]) jit->seen_reg[r1] = 1; } -- 2.30.2